Zimbabwe has declared a state of disaster as worsening food shortages threaten widespread famine.

The disaster declaration, which is effective for three months, will give President Robert Mugabe the authority to order "extraordinary measures" to deliver food to those in need.

The Zimbabwean Government has blamed the crisis on a drought, but the World Food Programme says that agricultural disruption caused by the confiscation of white-owned farms has also contributed to the problem.

President Mugabe will have special powers to tackle the crisis

The BBC's Lewis Machipisa, in Harare, says the declaration is an SOS signal to donors and international relief agencies.

It allows aid agencies to set up emergency
programmes for the estimated 7.8 million of the country's 13 million population in need of urgent food aid.

Earlier this year, the government banned aid groups from distributing food, claiming they were using the relief to campaign for the opposition MDC.

The food shortages are mirrored in Malawi and Mozambique, where poor harvests and erratic rains have led to famine.

"As a result of the prevalent drought, a state of disaster exists in all communal lands, resettlement and urban areas in
Zimbabwe," Mr Mugabe said in a
government statement reported by The Herald newspaper on Tuesday.

Emergency measures are expected to include possible commandeering of transport and other facilities to distribute food.

Zimbabwe consumes about two million tonnes of corn - its staple food - every year, but this year harvests are forecast at 750,000 tonnes.

Last year's crop was 1.4 million tonnes which was itself below average, research agencies said. The country was once a net grain exporter.

Drought worsens

Farmers have described the drought during the past agricultural season as the worst in 50 years.

UN agencies launched a programme
earlier this year to feed about 750,000 people facing starvation in the worst affected rural areas.

But only one-third of the emergency food needed has been delivered.

Millions are also at risk in Malawi and Mozambique

The government ordered 200,000 tonnes of corn worth $25m from South Africa in January.

But less than half has been delivered because of financing and logistical problems, according to a report of the UN Relief and Recovery Unit in Harare.

Last month, Agriculture Minister Joseph Made said the government was also seeking an extra 200,000 tons of corn from Kenya, Brazil and Argentina.

Officials say the disaster declaration is a step towards speeding up the delivery of food pledged by donors.

Economic woes

Zimbabwe's troubled economy is also contributing to the problem.

Inflation is at a record 113%; the economy is shrinking and there are shortages of hard currency which, says the government,
means food imports can only be bought with aid.

The European Union and the United States have announced targeted sanctions against government leaders to protest
against alleged human rights abuses and the March presidential elections which many international observers said were flawed.

Farming disruptions have led to a 30% decline in forecast harvests this year of tobacco, the main hard currency earner.

Mining has been plagued by shortages of
equipment and fuel, and tourism, another key money earner, has fallen by 80%.